1. Field of the Invention
The present invention generally relates to a method of controlling a vehicle while operating under a cruise control. More specifically, the present invention relate to a method that generates preliminary braking force prior to the operation of the brakes by the driver, and improves response to driver brake operation and shortens the free running distance.
2. Background Information
In recent years, many vehicles have been equipped with various automatic speed control technologies. For example, an adaptive cruise control system has been disclosed in U.S. Pat. No. 6,311,120 that is capable of executing a following control function. In such an automatic speed control device, when a host vehicle (an ACC vehicle) is traveling in a following control mode in which a host vehicle (an ACC vehicle) is automatically follow a preceding vehicle, the automatic speed control device maintains the host vehicle's distance from the preceding vehicle at a desired inter-vehicle distance. In particular, the automatic speed control device controls the host vehicle's speed so that the host vehicle is automatically accelerated up to a preset vehicle speed, when the preceding vehicle itself changes its traffic lane and disappears from the host vehicle's driving lane. On the other hand, when the preceding vehicle actually exists ahead of the host vehicle but an inter-vehicle distance sensor, employed in the host vehicle, loses the track of the preceding vehicle owing to various factors, for example, curves, slopes, weather or the like, the device disclosed in Japanese Laid-Open Patent Application No. 11-192858 maintains or holds the host vehicle's speed at a vehicle speed given at the time when the preceding vehicle has been lost, until such time that the host vehicle reaches a lost point where the preceding vehicle has been lost, so as to inhibit the automatic accelerating mode from being initiated and to prevent the host vehicle's distance from the preceding vehicle from being reduced inadvertently or undesirably.
There is also known a preliminary braking force control device that generates a preliminary braking force prior to operation of the brakes by the driver, thereby improving response to brake operation by the driver and shortening the free running distance. One such preliminary braking force control device is disclosed in Japanese Laid-Open Patent Application No. 2000-309257.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved a method of controlling a vehicle while operating under a cruise control. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.